What is a biostimulant?

Biostimulants are increasingly attracting the attention of professionals because they offer a new way to support crop growth and vitality. Their role is not to provide nutrients, but to activate biological processes that allow plants to better utilize available resources, strengthen their resilience, and fully express their potential. Focusing on biostimulants means taking a fresh look at plant physiology, soil dynamics, and the interactions that shape the performance of a cropping system.

Definition and regulatory positioning

Biostimulants now occupy a clearly defined place in the landscape of agricultural inputs. According to European Regulation 2019/1009, they are described as fertilizers capable of stimulating plant nutrition processes , regardless of the nutrients they contain. Their role is to improve nutrient use efficiency, plant tolerance to abiotic stresses, certain quality criteria of production, and the availability of elements in the soil and rhizosphere.

This definition clearly distinguishes biostimulants from other categories of inputs: they are neither fertilizers nor biocontrol products. They constitute a separate family, focused on plant physiology and soil biological activity.

Since the entry into force of the Fertilizers and Growing Media (MFSC) Regulation in July 2022, this positioning has become the regulatory basis for their marketing. A biostimulant can act on different mechanisms: directly on the plant, on the rhizosphere, or on the soil itself. Some products even combine fertilizers or soil amendments with a biostimulant additive, in order to combine nutrient input with the stimulation of natural processes.

What are the recognized properties and effects of biostimulants?

Biostimulants act on several key levers of plant and soil functioning. Their value lies in a combination of effects which, taken together, improve overall crop performance.

• improved absorption of nutrients present in the environment or supplied by fertilizers;
• increased bioavailability of soil nutrients, facilitating their mobilization and use by plants;
• strengthening tolerance and resilience to abiotic stresses such as drought, excess water, frost or salinity;
• improvement of qualitative criteria : content of compounds (sugars, lipids), more homogeneous colour, better preservation;
• optimization of microbial activity and physico-chemical properties of soils , with a positive effect on the degradation of organic matter;
• potential economic gains through better valuation of inputs and more regular returns;
• environmental benefits linked to a reduction in the use of non-renewable resources for fertilization.

What abiotic stresses are targeted by biostimulants?

Crops experience stress episodes each year that disrupt their functioning. Biostimulants were specifically developed to help plants better withstand these variations by strengthening their metabolic capacities and adaptation mechanisms.

They provide significant support in several situations:

• frost and low temperatures during sensitive stages;
• water stress, both in the case of water deficit and excess;
• intense heat disrupts photosynthesis and flowering;
• variations in brightness, whether it be an excess or a lack;
• salinity, which affects the absorption of water and nutrients;
• certain nutritional deficiencies, particularly when the soil fails to release sufficient elements.

To fully exploit their potential, biostimulants must be incorporated before these sensitive periods. Early application allows plants to activate their biological processes before stress sets in, rather than as a delayed response.

This approach requires a holistic perspective: knowledge of the soil, careful observation of crops, and anticipation of climatic constraints. When integrated into this strategy, biostimulants become a reliable tool for supporting the resilience of cropping systems.